FIG. 1 schematically shows a lamp 1, comprising one or more actual light-generating elements 2, mounted on a base 3. A voltage source or current source for the light-generating element(s) 2 may be arranged in the base 3, and may comprise a battery (not shown) as a power source or a power cord with connector 4 for connection to the electric mains. The light-generating element(s) 2 may be implemented as an incandescent light bulb, or a gas discharge element such as for instance TL or PL, or an LED.
The lamp 1 further comprises a cap or shade 5. The shade 5 serves, on the one hand, to protect the light generating element 2 and, on the other hand, it serves an ornamental purpose. The shade 5 is typically diffusely transparent, so that the light generating element 2 is hidden from direct view, whereas, when the light generating element 2 is ON, it illuminates the shade 5. The shape of the shade 5 will vary, depending on the shape of the lamp 1. In the embodiment illustrated schematically, the shade 5 has the shape of a part of a cone, but the shade 5 may alternatively for instance have a ball shape, a cylindrical shape, a box shape, or any other shape enclosing the light generating element 2. The lamp has an intrinsic orientation for being mounted on a wall or, as in the illustration, placed on a surface, in which case the lamp has an upper side and a lower side; the directions “vertical” and “horizontal” will be used in relation to this orientation. In a free-standing embodiment, the shade 5 will surround the light generating element 2 over 360° in the horizontal direction, but in a wall-mounted embodiment, the shade 5 will surround the light generating element 2 over 180° in the horizontal direction.